The present invention relates generally to electrochemical deposition methods and, more particularly, to electrochemical deposition methods for depositing thin-film cells containing non-toxic elements.
Thin-film photovoltaic cells are made by depositing thin layers of photovoltaic material. The photovoltaic layers include p-type and n-type layers. These layers can be made from a variety of photovoltaic materials and can be deposited using a variety of techniques.
The most commonly used materials for p-type layers include chalcopyrite materials, such as, copper indium gallium selenide (CIGS) and cadmium telluride (CdTe) which are toxic materials. The CIGS and CdTe layers are commonly deposited using methods including co-evaporation, sputtering, electrodeposition and colloidal deposition. The most commonly used material for the n-type layer is cadmium sulfide (CdS) which is also toxic. The CdS layer is commonly deposited using either sputtering or a chemical bath deposition.
There is a need to include a broader range of materials for use in thin-film photovoltaic cells. Specifically, there is a need for thin-film photovoltaic cells that use materials that are less toxic to the environment and that contain elements that are low cost and are more abundant in nature. In addition, there is a need for a process of depositing thin-film cells that offers low-cost processing and the ability to introduce a variety of different alloy materials as p-type and n-type layers.